Vehicle suspension structures are well-known in the art. In particular, vehicle suspension structures having arms suspended from a vehicle frame and a wheel-bearing axle suspended from the trailing arm are known. An example of this type of vehicle suspension structure is disclosed in the Bird U.S. Pat. No. 3,547,215 issued Dec. 15, 1970. As in the patent to Bird, a square axle is typically welded to a bracket which is, in turn, secured to the trailing arm of the vehicle suspension structure. The weldment securing the axle to the bracket is usually made at the midpoint of the side where vertical bending moment stresses are neutral. However, these areas are areas of high torsional loading which results from brake torque, vehicle roll and diagonal axle (wheel) walk. The welding at the midpoint of the axle typically introduces a point of weakness where axle failure may initiate. The weakness in the typical axle welded to a bracket is caused, in part, by the undesirable heat-treating effects of the welding process upon the axle material in the localized area adjacent the weldment. In addition, craters or strike marks may form points at which cracks may initiate or at which stresses may become concentrated.
The typical axle is welded to the bracket by a line weld on either side of the bracket. Because it is a line weld, the weldment has "ends" at which stresses are concentrated and at which cracks may initiate.
The typical axle is difficult to install because the axle must be held in place against the axle bracket while extensive welding takes place. This structure both increases assembly time and increases the heat of welding with its resultant undesirable localized heat treatment of the base metal.
Other suspension assemblies include those disclosed in: the Henry et al. U.S. Pat. No. 3,707,298, issued Dec. 26, 1972 which discloses an axle permitted to rock within a recepticle. Rocking is yieldably resisted by an elastomer material; the Sudberry U.S. Pat. No. 3,799,571, issued Mar. 26, 1974 which discloses an axle clamped to a leaf spring by a U-bolt assembly; the Raidel U.S. Pat. No. 3,043,606, issued July 10, 1962 which discloses an axle secured immovably to a seat member by a line of weldments; the Brown U.S. Pat. No. 923,135, issued June 1, 1909 which discloses an axle secured within a U-shaped member; the Cartwright U.S. Pat. No. 1,306,685, issued June 17, 1919 which discloses an axle suspended beneath a leaf spring by means of a U-bolt assembly; the Dorn U.S. Pat. No. 1,196,436, issued Aug. 29, 1916 which discloses an axle secured by U-shaped clips to a hood; and Chamberlain U.S. Pat. No. 4,016,947, issued Apr. 12, 1977 which discloses a clamp assembly for securing an axle housing relative to a vehicle frame; the West German Patent Auslegeschrift No. 16 80 052, issued July, 1977, discloses an axle secured within U-clamps to a trailing arm assembly; the Slemmons et al. U.S. Pat. No. 2,773,698, issued Dec. 11, 1956 which discloses an axle suspended beneath a trailing arm by means of arcuate lines of welding securing the axle to semi-cylindrical shells.
The typical axle/axle bracket connection, however, weakens the structural integrity of the axle. This weakness is caused by the extent and location of welding necessary to secure the axle in place.